Terminal connector for terminal bushings



Aug. 31, 1965 o. H. SOLES ETAL 3,204,022

TERMINAL CONNECTOR FOR TERMINAL BUSHING-5 Filed April 20, 1962 2Sheets-Sheet 1 230 Fig. 4

! l l l ['2 I20] I tINIXESNTIORSa Of 0 oes mm Carl 6. Lenfjes 3 MM ,9 a?-h ATTORNEY 1, 1965 o. H. SOLES ETAL 3,204,022

TERMINAL CONNECTOR FOR TERMINAL BUSHINGS Filed April 20, 1962 2Sheets-Sheet 2 United States Patent '0 3,204,022 TERMINAL CONNECTOR 'FORTERMINAL BUSHINGS Otto H. Soles, North Huntingdon Township, WestmorelandCounty, and Carl G. Lentjes, Churchill, Pa., assignors to, WestinghouseElectric Corporation, East Pittsburgh, Pa., a corporation ofPennsylvania Filed Apr. 20, 1962, Ser. No. 189,090 '3 Claims. (Cl.174-75) This invention relates to terminal connectors for terminalbushings in general and, more particularly, to an improvedterminal-connector construction for a terminal bushing for readilyadapting the same for interchangeable use with circuit breakers andtransformers.

A general object of the present invention is to provide I an improvedterminal connector for a terminal bushing involving few parts, beingeconomical to manufacture, having a reduced height for the terminalbushing and enabling rapid change-over from circuit-breaker use totransformer use.

A more specific object of the present invention is the provision of animproved terminal-connector construction for a terminal bushingeliminating bolted joints as far as possible, requiring few parts andenabling rapid change-over from circuit-breaker to transformer use.

According to one feature of the present invention, a plug-like terminalcap adaptable for attachment to the transformer lead is inserted Withinthe outer end of the tubular conductor stud and fixedly secured intoplace by the external enveloping terminal cap of the terminal bushing.Preferably, the enveloping cup-like terminal cap is of bifurcatedconstruction and is clamped into place by the clamping action of theclamp bolt associated therewith.

Further objects and advantages will readily become apparent upon readingthe following specification, taken in conjunction with the drawings, inwhich:

FIGURE 1 is a side elevational view of a terminal bushing embodying thepresent invention;

FIG. 2 is an enlarged vertical sectional view taken through the improvedterminal-connector construction of the present invention and illustratesthe adaptation of the terminal bushing for circuit-breaker use;

FIG. 3 is a fragmentary vertical sectional view taken through theimproved terminal-connector construction of the present inventionemploying the plug-like terminal cap and illustrating the adaptation ofthe terminal bushing for transformer use; and,

FIG. 4 is a detailed end view of the plug-like terminal connector cap ofthe present invention.

Referring to the drawings, and more particularly to FIG. 1 thereof, thereference numeral 1 generally designates a terminal bushing which may beadaptable for interchangeable use in connection with circuit breakers orwith transformers. As shown, the terminal bushing 1 ineludes an externalweatherproof shell 2, a mounting flange assembly 3, a lowerinteriorly-disposed porcelain shell 4 and a clamping ring 5. As shown,the terminal bushing 1 is adaptable for mounting to a flange ring 6associated with a collar support 7 welded, as at 8, to the cover 9 of anenclosing structure or tank 10.

As well known by those skilled in the art, the enclosing tank structure10 may be utilized for circuit breaker use, as illustrated in FIG. 1, orfor transformer use, the circuit breaker unit 11 being threadedlysecured and clamped to the lower end 12a of the tubular terminal stud 12extending axially through the terminal bushing 1. For transformer use,the flexible lead from the transformer winding, not shown, is threadedthrough the tubular terminal stud 12 and is secured to the cap structure14 3,204,022 I Patented Aug. 31, 1965 associated with the external endof the terminal bushing 1 in a manner more fully described hereinafter.

FIG. 2 more clearly illustrates the improved terminal cap construction13 associated with the terminal bushing 1. As shown, the tubularconductor stud 12, extending axially through the terminal bushing 1, hasfixedly secured thereto, as by soldering, for instance a mounting ring17, the latter in turn being secured, as by soldering, to the cap shellshell 18. As well known by those skilled in the art, the cap shell 18encloses suitable compression springs, not shown, which place theporcelain shells 2, 4 and the flange assembly 3 into compression, whileat the same time exerting tensile stress upon the elongatedaxially-extending tubular conductor stud 12.

As shown in FIGS. 1 and 2, for circuit-breaker use, a cup-shapedexternal enveloping terminal connector 19, preferably of splitbifurcated construction, has a clamping bolt 19a associated therewith,and cooperates with the upper extremity 12b of the tubular conductorstud 12 to fixedly clamp the two together in good contacting engagement.An annular gasket 21 may be interposed between the end extremity 12b ofconductor stud 12 and the base 22 of the terminal connector 19.

For transformer use, the same construction with the addition of theplug-like terminal cap 23 may be employed, as shown in more detail inFIG. 3 of the drawings. As illustrated, the terminal cap 23 has a cavity23a provided therein, within which may be inserted and fixedly secured,as by soldering, the terminal lead 24 associated with a transformer, notshown. By providing a spherical contact seat 25 there resultscooperation between an indented surface area 22a of the terminalconnector 19 and the spherical contact surface 25 so that goodcontacting engagement is provided. FIG. 4 illustrates in more detail theparticular construction of the plug-like terminal cap 23.

From the foregoing, it will be apparent that for transformer use theterminal cap 23 may be fixedly secured to the lead 24 of an associatedtransformer, and clamped into engagement with the terminal bushing end1211, as illustrated in FIG. 3 of the drawings. For circuit-breaker use,on the other hand, the terminal cap 23 may be omitted altogther, and theconstruction, as shown in FIGS. 1 and 2, may be employed.

From the foregoing, it will be apparent that there is provided animproved simplified terminal-connector construction 13 for a terminalbushing 1 adapting the same for interchangeable circuit-breaker use andfor transformer use. There are utilized only few parts adapted foreconomical manufacture, and also the overall height of the terminalbushing 1 may be somewhat reduced by an application of the presentinvention. This is of some importance during shipment of circuitbreakers or transformers to expedite travel in tunnels, etc.

The present invention offers a simple and efficient method ofinterchanging circuit-breaker bushings and the transformer bushings.Change-over is quickly accomplished in the field. There is merelynecessitated the removal of the terminal 19 and insertion of theplug-like terminal cap 23 into place within stud 12. The terminal 19 maythen be screwed back into place and fixedly clamped into position bytightening clamp bolt 19a. The present invention has the advantage ofeliminating as far as possible bolted joints, and also eliminatescomplicated assembly items as there are no soldered joints or mountinghardware. In addition, it requires no extra parts and transformerchangeover may readily be made with the use of the plug 23. As a result,changeover is quick and efiicient. Simplicity of construction andconsiderably reduced costs are effected by the elimination of thesoldered joint and flanged bolted joint, as employed in some priorartconstructions.

illustrated and described a par- 7,

2. The combination of claim 1, wherein a threaded engagement is providedbetween the end of the tubular able transformer and circuit-breaker usehaving a tubular conductor stud for transmitting the currenttherethrough when in circuit-breaker use, the combination therewith of aunitary plug-like insertable terminal cap having a cavity providedtherein for the reception of the end of a transformer lead, said unitaryterminal cap having a radially outwardly extending end flange portionseated upon the end extremity of the tubular conductor stud and havingan integrally-formed tubular shank portion surrounding said cavityinserted within the extremity of the tubular conductor stud, and anouter enveloping terminal cap enclosing the end of the tubular conductorstud and pressurally engaging the outer end of the unitary insertableterminal cap to form an electrical connection between said unitaryterminal cap and said enveloping terminal cap.

conductor stud and the outer enveloping terminal cap.

3. A terminal bushing according to claim 1 wherein the end flangeportion of the unitary insertable terminal cap is additionallycharacterized as having a substantially spherical end surface, and theinner surface of the enveloping terminal cap is additionallycharacterized as having a substantially centrally disposed indentedsurface area into which a portion of the spherical surface of the flangeportion of the unitary insertable terminal cap extends while theenveloping terminal cap is secured to the end of the conductor stud, thespherical surface and indented surface area cooperating to provide alarge current carrying surface contact area.

References Cited by the Examiner UNITED STATES PATENTS 8/32 Burr 17474 X10/33 Calloway a 174-75

1. IN THE TERMINAL BRUSHING ADAPTABLE FOR INTERCHANGEABLE TRANSFORMERAND CIRCUIT-BREAKER USE HAVING A TUBULAR CONDUCTOR STUD FOR TRANSMITTINGTHE CURRENT THERETHROUGH WHEN IN CIRCUIT-BREAKER USE,THE COMBINATIONTHEREWITH OF A UNITARY PLUG-LIKE INSERTABLE TERMINAL CAP HAVING A CAVITYPROVIDED THEREINFOR THE RECEPTION OF THE END OF A TRANSFORMER LEAD, SAIDUNITARY TERMINAL CAP HAVING A RADIALLY OUTWARDLY EXTENDING END GLANGEPORTION SEATED UPON THE END EXTREMITY OF THE TUBULAR CONDUCTOR STUD ANDHAVING AN INTEGRALLY-FORMED TUBULAR SHANK PORTION SURROUNDING SAIDCAVITY INSERTED WITHIN THE EXTREMITY OF THE TUBULAR CONDUCTOR STUD, ANDAN OUTER ENVELOPING TERMINAL CAP ENCLOSING THE END OF THE TUBULARCONDUCTOR STUD AND PRESSURALLY ENGAGING THE OUTER END OF THE UNITARYINSERTABLE TERMINAL CAP TO FORM AN ELECTRICAL CONNECTION BETWEEN SAIDUNITARY TERMINAL CAP AND SAID ENVELOPING TERMINAL